Angiogenesis plays crucial roles in tumor growth, progression and metastasis. Non-invasive in vivo imaging of tumor neovasculature is a fundamental prerequisite for effective therapeutic intervention, particularly anti-angiogenic treatment regimens. Emerging molecular imaging techniques now allow recognition of cellular/molecular processes before gross pathological changes, leading to better understanding of fundamental biological processes of tumor angiogenesis. In this review, we will summarize recent progresses on molecular imaging of attractive biochemical epitopes in tumor angiogenesis, especially the endothelial cell targets-based imaging probes.